aboutsummaryrefslogtreecommitdiff
path: root/drivers/watchdog/bcm47xx_wdt.c
blob: b4021a2b459b6c0889173a30f89d4d365eb8e9f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
/*
 *  Watchdog driver for Broadcom BCM47XX
 *
 *  Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs>
 *  Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr>
 *  Copyright (C) 2012-2013 Hauke Mehrtens <hauke@hauke-m.de>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/bcm47xx_wdt.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include <linux/timer.h>
#include <linux/jiffies.h>

#define DRV_NAME		"bcm47xx_wdt"

#define WDT_DEFAULT_TIME	30	/* seconds */
#define WDT_SOFTTIMER_MAX	255	/* seconds */
#define WDT_SOFTTIMER_THRESHOLD	60	/* seconds */

static int timeout = WDT_DEFAULT_TIME;
static bool nowayout = WATCHDOG_NOWAYOUT;

module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default="
				__MODULE_STRING(WDT_DEFAULT_TIME) ")");

module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd)
{
	return container_of(wdd, struct bcm47xx_wdt, wdd);
}

static int bcm47xx_wdt_hard_keepalive(struct watchdog_device *wdd)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);

	wdt->timer_set_ms(wdt, wdd->timeout * 1000);

	return 0;
}

static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd)
{
	return 0;
}

static int bcm47xx_wdt_hard_stop(struct watchdog_device *wdd)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);

	wdt->timer_set(wdt, 0);

	return 0;
}

static int bcm47xx_wdt_hard_set_timeout(struct watchdog_device *wdd,
					unsigned int new_time)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
	u32 max_timer = wdt->max_timer_ms;

	if (new_time < 1 || new_time > max_timer / 1000) {
		pr_warn("timeout value must be 1<=x<=%d, using %d\n",
			max_timer / 1000, new_time);
		return -EINVAL;
	}

	wdd->timeout = new_time;
	return 0;
}

static struct watchdog_ops bcm47xx_wdt_hard_ops = {
	.owner		= THIS_MODULE,
	.start		= bcm47xx_wdt_hard_start,
	.stop		= bcm47xx_wdt_hard_stop,
	.ping		= bcm47xx_wdt_hard_keepalive,
	.set_timeout	= bcm47xx_wdt_hard_set_timeout,
};

static void bcm47xx_wdt_soft_timer_tick(unsigned long data)
{
	struct bcm47xx_wdt *wdt = (struct bcm47xx_wdt *)data;
	u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms);

	if (!atomic_dec_and_test(&wdt->soft_ticks)) {
		wdt->timer_set_ms(wdt, next_tick);
		mod_timer(&wdt->soft_timer, jiffies + HZ);
	} else {
		pr_crit("Watchdog will fire soon!!!\n");
	}
}

static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);

	atomic_set(&wdt->soft_ticks, wdd->timeout);

	return 0;
}

static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);

	bcm47xx_wdt_soft_keepalive(wdd);
	bcm47xx_wdt_soft_timer_tick((unsigned long)wdt);

	return 0;
}

static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);

	del_timer_sync(&wdt->soft_timer);
	wdt->timer_set(wdt, 0);

	return 0;
}

static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd,
					unsigned int new_time)
{
	if (new_time < 1 || new_time > WDT_SOFTTIMER_MAX) {
		pr_warn("timeout value must be 1<=x<=%d, using %d\n",
			WDT_SOFTTIMER_MAX, new_time);
		return -EINVAL;
	}

	wdd->timeout = new_time;
	return 0;
}

static const struct watchdog_info bcm47xx_wdt_info = {
	.identity	= DRV_NAME,
	.options	= WDIOF_SETTIMEOUT |
				WDIOF_KEEPALIVEPING |
				WDIOF_MAGICCLOSE,
};

static int bcm47xx_wdt_notify_sys(struct notifier_block *this,
				  unsigned long code, void *unused)
{
	struct bcm47xx_wdt *wdt;

	wdt = container_of(this, struct bcm47xx_wdt, notifier);
	if (code == SYS_DOWN || code == SYS_HALT)
		wdt->wdd.ops->stop(&wdt->wdd);
	return NOTIFY_DONE;
}

static struct watchdog_ops bcm47xx_wdt_soft_ops = {
	.owner		= THIS_MODULE,
	.start		= bcm47xx_wdt_soft_start,
	.stop		= bcm47xx_wdt_soft_stop,
	.ping		= bcm47xx_wdt_soft_keepalive,
	.set_timeout	= bcm47xx_wdt_soft_set_timeout,
};

static int bcm47xx_wdt_probe(struct platform_device *pdev)
{
	int ret;
	bool soft;
	struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);

	if (!wdt)
		return -ENXIO;

	soft = wdt->max_timer_ms < WDT_SOFTTIMER_THRESHOLD * 1000;

	if (soft) {
		wdt->wdd.ops = &bcm47xx_wdt_soft_ops;
		setup_timer(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick,
			    (long unsigned int)wdt);
	} else {
		wdt->wdd.ops = &bcm47xx_wdt_hard_ops;
	}

	wdt->wdd.info = &bcm47xx_wdt_info;
	wdt->wdd.timeout = WDT_DEFAULT_TIME;
	ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout);
	if (ret)
		goto err_timer;
	watchdog_set_nowayout(&wdt->wdd, nowayout);

	wdt->notifier.notifier_call = &bcm47xx_wdt_notify_sys;

	ret = register_reboot_notifier(&wdt->notifier);
	if (ret)
		goto err_timer;

	ret = watchdog_register_device(&wdt->wdd);
	if (ret)
		goto err_notifier;

	dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
		timeout, nowayout ? ", nowayout" : "",
		soft ? ", Software Timer" : "");
	return 0;

err_notifier:
	unregister_reboot_notifier(&wdt->notifier);
err_timer:
	if (soft)
		del_timer_sync(&wdt->soft_timer);

	return ret;
}

static int bcm47xx_wdt_remove(struct platform_device *pdev)
{
	struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);

	if (!wdt)
		return -ENXIO;

	watchdog_unregister_device(&wdt->wdd);
	unregister_reboot_notifier(&wdt->notifier);

	return 0;
}

static struct platform_driver bcm47xx_wdt_driver = {
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "bcm47xx-wdt",
	},
	.probe		= bcm47xx_wdt_probe,
	.remove		= bcm47xx_wdt_remove,
};

module_platform_driver(bcm47xx_wdt_driver);

MODULE_AUTHOR("Aleksandar Radovanovic");
MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
MODULE_LICENSE("GPL");